WHY FIVE MEALS IN WEIGHT LOSS DIETS?

WHY FIVE MEALS IN WEIGHT LOSS DIETS?
INTRODUCTION
Satiety is regulated by several hormones, some of them are implicated in the regulation of gastrointestinal motility, whereas another
modulate energy balance. Hence, these hormones ultimately play a role in body weight regulation.
The regulation of gastrointestinal motility is mainly produced by two types of mechanisms: mechanical (distension of the stomach) and
hormonal. Those are described in this paper focus on signals coming from the stomach, duodenum and distal small intestine.
Metabolism also influences in the regulation of eating and body weight by two hormones called adiposity: leptin and insulin.
OBJECTIVES
The main objective is to explain the benefits of doing 5 meals a day, as recommended in slimming diets.
To explain clearly and concisely which is the impact of a diets including 5 meals, this paper is focused on the following points:
- Describe the impact on satiety of several mechanisms involved in the regulation of gastrointestinal motility.
- Describe the involvement of insulin and leptin in the regulation of satiety.
- Explain how the issues discussed in the previous points affect the control of body weight.
REGULATION OF GASTROINTESTINAL MOTILITY AND ITS INVOLVEMENT IN SATIETY
Hormone
Ghrelin
Cholecystokinin (CCK)
Glucagon-like peptide-1 (GLP-1)
Peptide tyrosine tyrosine (PYY)
Where is synthesized
Functions
Fundus of the stomach and other parts of Increases food intake, gastrointestinal
the gastrointestinal tract
motility and decreases insulin secretion
Reduces intake, enhances the motility of
the gallbladder to expel bile into the small
Mucosa of the small intestine when the
intestine, where it plays an important
long-chain fatty acids and proteins reach
mission in the fat emulsion, inhibits
the duodenum
contraction and delays gastric emptying of
the stomach.
Regulates blood sugar, stimulates insulin
gene expression, attenuates blood sugar,
inhibits hepatic glucose production and
stimulates glucose uptake in both adipose
Distal small intestine
tissue and muscle. Reduces fatty acids and
postprandial concentrations of
triglycerides, slows gastric emptying, acid
secretion, and food intake
Distal small intestine. Ingested fats are a Inhibits sensations of appetite and food
strong stimulus for the release of PYY
intake.
REGULATION OF SATIETY
Insulin: controls glucose levels in blood. Glucose and serotonin are able to regulate their release. Metabolic and endocrine factors along with
nerve signals control insulin production in the pancreas and its secretion, and have a direct impact on circulating levels of insulin and its
transport to the brain.
Leptin: Its normal production and action are critical to maintain balance of power. Insulin is the main regulator of leptin production by
adipose tissue. Decreases circulating leptin during energy restriction and is related to increased hunger in humans. Therefore, decreasing
dietary intake during weight loss can contribute to the strong tendency to weight recovery.
CONCLUSIONS
Divide food into five meals a day in small amounts and frequently, helps the body
maintain optimal energy levels, preventing downloads of glucose throughout the day.
This way of eating helps digestion and regulates appetite feeling less hungry to get to
the main meals and avoid eating more.
Furthermore, these meals should include especially long-chain fatty acids, to promote
the release of CCK and PYY, GLP1 and the latter are mediators ileal brake. GLP-1 also
enhances insulin secretion, which together with the above factors mean that there is
an increased feeling of satiety.
Picture 1: Adapted from Cummings & Overduin, 2007
Estela Soriano Egea